A global pandemic certainly qualifies as "unusual circumstances." 

That was the wording Notre Dame athletic director Jack Swarbrick used to explain why the school is joining the ACC in football for the 2020 season. Swarbrick explained to ESPN's Heather Dinich that maintaining the Fighting Irish's traditional independence left too much to chance:

"This is just an unprecedented and extraordinary year, and you recognize that going in. Could we have constructed a schedule without this? Yes, but given the uncertainties that everybody faces, you couldn't exactly be sure what you have. There was a greater level of control and certainty if we could do this with the ACC than if we had just constructed the schedule ourselves."

Notre Dame aligned with the ACC for everything but football in 2012. As part of that deal, the Fighting Irish committed to playing a handful of games on the gridiron against ACC schools every year.

The conference announced Wednesday the program would go a step further for 2020. Notre Dame will play 10 ACC opponents and be eligible for the conference championship game.

ESPN's Andrea Adelson first reported July 24 this was a possibility and laid out why it was the most equitable solution for all parties.

The Big Ten and Pac-12 have already adopted conference-only schedules, costing Notre Dame games against Stanford, USC and Wisconsin. Now, the Fighting Irish have more scheduling stability and need to find only one nonconference opponent.

The ACC, meanwhile, doesn't have to worry about jeopardizing Clemson, Louisville and Georgia Tech's ability to pursue their annual rivalry games. If Notre Dame didn't formally join the ACC, then it would've potentially counted as a nonconference foe for the Tigers, Cardinals and Yellow Jackets.

According to Dinich, Notre Dame "is evaluating its non-ACC opponents" ahead of finalizing its 2020 schedule.

While Clemson will be heavily favored to win a sixth straight ACC title, the Fighting Irish could derail the Tigers' quest for the College Football Playoff. ESPN.com's preseason Football Power Index listed Clemson at No. 1 and Notre Dame at No. 9 in February.

The Fighting Irish finished the 2019 season with an 11-2 record. Much of their 2020 fortunes will hinge on the right arm of Ian Book, who threw for 3,034 yards, 34 touchdowns and six interceptions last year.